/Engine/Source/Editor/PropertyEditor/Public/SStandaloneCustomizedValueWidget.h
Gets the thumbnail pool that should be used for rendering thumbnails in the struct
virtual [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [FAssetThumbnailPool](API\Editor\UnrealEd\FAssetThumbnailPool) > GetThumbnailPool() const